Modular physiological sensors that are physically and/or electrically configured to share a measurement site for the comfort of the patient and/or to ensure proper operation of the sensors without interference from the other sensors. The modular aspect is realized by providing outer housing shapes that generally conform to other physiological sensors； mounting areas for attachment of one sensor to another sensor； providing release liners on the overlapping sensor attachment areas； and/or providing notches, tabs or other mechanical features that provide for the proper placement and interaction of the sensors.
